Teen boy interested in eight year old girl! ?

I was watching my daughter play in the snow in our nieborhood and a thirteen year old boy that lives nearby started talking with her. They spoke at great length as I watched. This made me uncomfortable, so I asked my daughter to move close to the house and play. She did so, and so did the teen boy-I thought that by doing this the boy would be deterred. I then asked my daughter to play in the yard, thinking that this would put an end to it. It didn't, My daughter relocated to our small front yard and the boy also relocated, but he stayed on the edge of the nieghbors property and continued to have conversation with my daughter. My daughter was intrigued by the attention from this boy. I then requested my daughter to come inside, which she reluctantlly did. Am I being too overprotective? It just seems wierd for a 13 year old boy to have such interest in an eight year old girl.